I have mehran 2004 model. It was not running on petrol, missing and stops when in slow. i cleaned carburetor twice, cleaned jet but not success. The problem was in petrol tank, it was corroded and have dust in it due to broken petrol pipe (pipe which is used to insert petrol).

Last week, I replaced Petrol tank, pipe with new one, changed filter. The car was fine on high speed but when it was about to run in first gear , it gives a jerk. Mechanic said that it will be fine after sometime.

After 3-4 days, i started the car on petrol and same problem occurs again, it was stopping on low speed and giving jerks on high speed. i went to another mechanic and he cleaned jets in carburetor and he said that there is dust in tank. I don't know where does dust come in.

Petrol tank is half-full and i checked the petrol filter. The petrol inside filter is fine but in the bottom of filter there is little dust accumulated.

One friend said that the dust remained in petrol line / pipe from previous issue and its now back in tank. I am using petrol from yesterday, car is getting litter better now with usage, still jerks on slow speed but not stopping, should i continue using that petrol or dispose it?. Also should i again perform cleaning of every item like pipe, tank etc. or just replace filter and clean carburetor again ?